The science and technology change every day, and the semiconductor optoelectronic device contributes to the information transmission and the energy conversion. Taking the application of the system as an example, the semiconductor optoelectronic device contributes to the optic fiber communication, the optical storage and the military system. The semiconductor optoelectronic device is classified into three types according to the energy conversion: conversion from electricity into light emission such as light emitting diodes and laser diodes; conversion from optical signal into electronic signal such as optical detectors; conversion from light radiation into electricity such as solar cells.
The growth substrate is important for the semiconductor optoelectronic device. The semiconductor epitaxial structure of the semiconductor optoelectronic device is grown on the substrate which also provides the support function. Thus, choosing a suitable growth substrate is a key factor for the growth quality of the semiconductor optoelectronic device.
However, sometimes a good substrate for growing the device may not be a good substrate for supporting the device. Taking the light-emitting diode as an example, the opaque GaAs substrate is used to be the growth substrate to raise the growth quality of the device in the light emitting device dedicating to the red light emission, because the lattice constant of the GaAs is close to that of the semiconductor epitaxial structure. But for the light emitting device dedicating to the light emission, the opaque growth substrate reduces the light emission efficiency of the device during the operation.
A substrate transfer technology is developed to satisfy the different requirements of the growth substrate and the support substrate of the semiconductor optoelectronic device. The semiconductor epitaxial structure is grown on the growth substrate first, and then the semiconductor epitaxial structure is transferred to the support substrate for the following device operation. The removal of the original growth substrate is a key factor of the transfer method after combining the semiconductor epitaxial structure and the support substrate.
In the conventional technology, the removal method of the growth substrate includes: dissolving the original growth substrate with the etchant, physically polishing, or disposing a sacrificial layer between the growth substrate and the semiconductor epitaxial structure in advance and then separating the growth substrate and the semiconductor by etching the sacrificial layer. However, whether dissolving the substrate with the etchant or polishing the substrate physically, that is a kind of destruction for the original growth substrate. In the modern-day of environmental protection and energy conservation, the growth substrate not being re-used is undoubtedly a waste of the materials. However, how to selectively transfer is one of the research directions for the semiconductor optoelectronic device while using the sacrificial layer for separation purpose.